The present invention relates to a sliding universal joint to be mounted at a bending portion of a bendable drive axle in an automobile, for example. More particularly the invention is directed to an improvement in a joint including a cylindrical outer member connected to one transmitting shaft and having an inner periphery formed with a plurality of transmitting grooves arranged circumferentially equally spaced from each other and extending axially, an inner member connected to another transmitting shaft and having a plurality of trunnions radially extending to project into the transmitting grooves, an inner roller slidably engaged with an outer periphery of each trunnion, a holder relatively oscillatably engaging with an outer periphery of each inner roller, and an outer roller rotatably engaging with an outer periphery of each holder and engaged with the respective transmitting groove.
This type of universal joint is known as disclosed in Japanese Patent Publication No. 57-13211.
In the conventional joint, when both transmitting shafts are bent relative to each other during transmission of torque, the outer roller is reciprocatingly rolled in the transmitting groove permitting inclination of the trunnion. The inclination of the trunnion follows the inclination of the outer roller, causing an increase in rolling resistance of the outer roller and thus generating vibration.
The present invention has been achieved to solve the above problem, and it is an object of the invention to provide a sliding universal joint which may reliably prevent the outer roller being inclined in association with the inclination of the trunnion.
According to the present invention, there is provided in a sliding universal joint, the improvement comprising a restriction flange integrally formed with the holder, said restriction flange abutting against a bottom surface of the transmitting groove and restricting inclination of the holder.
With this arrangement, during rotation of the universal joint, restriction flange integrally formed with the holder is urged against the bottom surface of the transmitting groove by centrifugal force, thereby reliably maintaining an abutting condition of the flange against the bottom surface of the transmitting groove. Accordingly, even when the trunnion is inclined, the holder is reliably prevented from inclining because of the abutment of the restriction flange against the bottom surface of the transmitting groove. Accordingly, the outer roller supported by the holder is also prevented from inclining and can be smoothly rolled on the inner surface of the transmitting groove.